<!DOCTYPE html>
<html lang="en">
	<head>
		<meta charset="UTF-8" />
		<meta name="viewport" content="width=device-width, initial-scale=1.0" />
		<title>正则扩展-反向断言</title>
	</head>
	<body>
		<script>
			//声明字符串
			let str = "JS5211314你知道么555啦啦啦";
			//正向断言
			// const reg = /\d+(?=啦)/;
			// const result = reg.exec(str);

			//反向断言
			const reg = /(?<=么)\d+/;
			const result = reg.exec(str);
			console.log(result);
		</script>
	</body>
</html>
